As I said, up to 90% of suicide cases involve diagnosed mental illness of some kind while up to 53% involve the abuse of alcohol or drugs in some way. However, there are other causes also such as eating disorders and poor coping skills, as Senator Feighan pointed out. When one considers that between 10% and 20% of adolescents will have a major bout of depression at some point in their lives, there is an obvious link. This depression could arise because of an interpersonal conflict with a boyfriend or girlfriend, parent or school – one study shows that this is true of 70% of cases.